Tank car having sloping bottom

ABSTRACT

A cylindrical tank for use in railway tank cars, for example, having an inner bottom sloping from the ends of of the tank toward the center of the car for drainage purposes. A continuous slope plate structure is secured within each end portion of the cylindrical tank and slopes downwardly from the end of the tank to the center at a constant slope while tapering in width at a generally constant rate with an enclosed fluid-tight void space being formed between the bottom of the cylindrical tank and each slope plate. Each slope plate structure is generally arcuate as viewed in cross section and has an upwardly bowed convex upper surface to form a relatively narrow flow channel along each side of the slope plates directed toward the center of the car.

United States Patent Needham et a1.

TANK CAR HAVING SLOPING BOTTOM Inventors: Robert F. Needham, St. Charles;

Wallace T. Geyer, Des Peres, both of Mo.

Assignee: ACF Industries Incorporated, New

York, NY.

Filed: May 17, 1971 Appl. No.: 144,089

US. Cl. 105/360, 280/5 R Int. Cl B6111 5/00 Field of Search 105/358-360;

165/168; 280/5 R, 5 E, 5 K

[111 smas 51 Jul 3,1973

3,379,478 4/1968 Aller et a1 105/358 Primary ExaminerGerald M. Forlenza Assistant ExaminerRichard A. Bertsch Attorney-Eugene N. Riddle 5 7] ABSTRACT A cylindrical tank for use in railway tank cars, for example, having an inner bottom sloping from the ends of of the tank toward the center of the car for drainage purposes. A continuous slope plate structure is secured within each end portion of the cylindrical tank and slopes downwardly from the end of the tank to the center at a constant slope while tapering in width at a generally constant rate with an enclosed fluid-tight void space being formed between the bottom of the cylindrical tank and each slope plate. Each slope plate structure is generally arcuate as viewed in cross section and has an upwardly bowed convex upper surface to form a relatively narrow flow channel along each side of the slope plates directed toward the center of the car.

7 Claims, 11 Drawing Figures PATENTH] JUL 3 I975 sumura R 0 T N E V N ATTORNEY PATENTED JUL 3 I973 SIEEIJUFIB TANK CAR HAVING SLOPING BOTTOM BACKGROUND OF THE INVENTION It is highly desirable to have a tank bottom sloping from the ends toward the middle for the drainage of lading to a bottom outlet normally positioned at the longitudinal center of the car. Various arrangements have been designed to provide the so-called slope bottom for a tank car. For example, U.S. Pat. No. 3,282,228 issued Nov. 1, 1966, shows an arrangement in which an insert is positioned within a slot in a cylindrical section to provide a sloping bottom. US. Pat. No. 3,212,824 issued Oct. 19, 1965, discloses a separate arrangement in which cylindrical end portions are tilted and joined by a center section to provide a sloping bottom.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides for a railway tank car having a cylindrical tank, a bottom which slopes from the ends of the tank toward the center of the tank for discharge of liquids from a bottom discharge structure. The sloping bottom is provided without any change in the cylindrical tank by the addition of separate slope plates tapering from the end heads toward the center of the car and welded to the inner surface of the cylin drical tank. The'slope plates are generally arcuate as viewed in cross section and have upwardly bowed convex upper surfaces to form a relatively narrow flow channel along each side of the slope plates directly to ward the center of the car. This provides a very effective cleanout of the liquid lading within the car. The void volume between the slope plates and the tank shell may be utilized by filling with a polyurethane insulating material or heat coils may be arranged within this volume.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated,

FIG. 1 is a side elevation of arailway tank car embodying the present invention; I

FIG. 2 is an enlarged partial longitudinal section of the railway tank car shown in FIG. 1;

FIG. 3 is an enlarged section taken generally along line 33 of FIG. 2;

FIG. 4 is an enlarged section taken generally along line 44 of FIG. 2;

FIG. 5 is an enlarged section taken generally .along line 5-5 of- FIG. 2;

FIG. 6 is an enlarged section of the welded connection of the slope .plate to the tank shell;

FIG. 7 is a top plan of the slope plate shown removed from the railway tank car;

.FlG.-8 isa side elevation of an end of.a railwaytank car showing an embodiment of the invention in which a heating coil is provided beneath the slopeplate structure of the present invention;

FIG. 9 isa section taken generally along line9-9.of FIG.8 showing the arrangement.oftherheatingscoilbeneath the slope plate structure;

FIG. 10 is a sectionitaken generallyalongsline -10- 10 of FIG. 9; and

FIG. 11 is a section taken generally along line 11-41 of FIG. 8 illustrating the reinforcing pads for the end head.

Referring now to the drawings for a better understanding of this invention, and more particularly to the embodiment of FIGS. 1-7, a railway tank car is generally indicated 10 having a truck generally indicated 12 adjacent each end thereof. A coupler 14 is mounted within a stub center sill structure 16 beneath each end portion of the tank generally indicated 18. Tank or tank shell 18 has a bottom discharge outlet generally indicated 20 which may be manually actuated for the discharge of liquids from the tank. A manway structure 22 is provided adjacent the top of tank 18 to permit entry within the tank.

To provide a sloping bottom surface forthe liquid lading to drain from the bottom of tank 18 to bottom discharge outlet 20, a slope plate 24 is secured adjacent each end of the tank and slopes downwardly at a constant rate toward the longitudinal center of tank 18 for discharge from bottom discharge outlet 20. Referring particularly to FIG. 7, slope plate 24 is shown removed from tank 18 and has an arcuate outer end edge 26. Slope plate 24 tapers in width at a uniform rate from outer end edge 26 to inner end edge 28 and as will be explained further, is formed in two sections 24A and 24B connected by weld seam 30. As shown in FIGS. 3-15, slope plate 24 is arcuate and slopes downwardly from the end of tank 18 toward the center of the car at a constant slope of one-quarter inch per foot which is around one degree with respect to tank shell 18. The

arcuate or convex upper surface of slope plate 24 tends to divide the flow of liquid into two flow channels or troughs, one along each side of plate 24, each flow channel being relatively narrow in width and relatively deep in depth for effectively draining practically all liquid lading from tank 18 through discharge outlet 20.

As a specific example, tank l8'may have an inside diameter of 106 inches with a radius of 53 inches. As the half the :major axis R2 as shown in FIG. 2. Each end head H has two adjoining cylindrical sections or courses C1 and C2 welded thereto with each section.

Cl and C2 having a length, for example, of 9 feet. Weld seams W are X-rayed and then, a slope plate section 24A is placed within each of the assemblies consisting of a head II and two cylindrical sections C1 and C2. Slope plate section 24A has an outer end width of around 33 inches and an inner end width of around 18 inches and fits snugly against end head H with arcuate end edge 26 nesting against the adjacent arcuate portion of end head H. :In this position, section 24A is weldedxto the inner surfaces of end head [-1 and cylindrical-sections CI :and'C2. As sectionJ24A is shorter in length than the cylindricalsections C1 and C2, the free end of -section24A is withinsec tion C2.

Avoid space or volume 34 is formed between slope gplate 24 and tank shelll8 beneath plate 24. As shown particularly in FIGS. 2 and 5, asteam inlet 36 positioned along the. side of tank 18 may be provided to permit the-entry of steam within void volume 34 for the heating of ladings, such as pitch or the like, for unloading. A condensate outlet 37 is provided for the draining of void space 34 upon condensing of the steam.

In the event an insulated tank car is provided, the void area 34 may be filled with an insulating material, such as polyurethane foam material, to minimize a heat loss. Heat leaks occur quite frequently at the connection of the tank to the bolster and such leaks may be minimized by the addition of the insulating or expanding foam material within void volume 34. A suitable opening may be bored within tank shell 18 to provide access to the cavity or void 34 and an insulating foam material may be inserted therein. This opening may be closed with a screw-type plug if desired, to permit periodic inspection of the material in the void or to assure that liquid lading has not leaked into the cavity or void 34. In addition, insulating material, such as foam insulation illustrated at 38 in FIG. 6, in void space 34 acts to support slope plate 24 against deflection which might occur from pressure of the lading. Polyurethane foam materials of a rigid structure have a compressive strength which might aid in reducing the thickness of the slope plate yet will be resilient enough to deflect slightly when the tank shell undergoes a deformation.

The body bolster is generally indicated at 40 and has a lower bolster cover plate 42. A cradle 44 is secured at the bolster area about substantial portion of the circumference of tank shell 18. A cradle pad 46 is positioned between the outer surface of tank shell 18 and the upper surface of stub sill 16. Cradle pad 46 extends rearwardly beyond stub center sill 16 and aids in trans-.

fer of the forces between tank shell 18 and stub center sill 16. To reinforce end heads H, a cradle pad extension 46A forms a continuation of cradle pad 46 and is secured to end head Has shown particularly in FIGS. 8 and 11. A wedge-shaped reinforcing member 50 is welded between the upper surface of center sill 16 and cradle pad extension 46A. Thus, end head H is pro tected and reinforced by the combination of cradle pad extension 46A and wedge-shaped reinforcement 50.

Next, center section C3 having manway structure 22 and bottom outlet 20 thereon is welded along weld lines W] to adjacent sections C2 thereby to complete the cylindrical tank 18. Weld seams W1 are X-rayed and slope plate sections 24B are inserted through the opening of around 20 inches in diameter formed by manway 22 and are welded to the adjacent end edges of slope plate sections 24A and to the inside surfaces of sections C2 and C3. After welding of slope plate sections 248, the tank thus formed is stress relieved by placing within a heat furnace for around 6 hours at llF.

In some instances, depending on the capacity of the tank car and the length of the cylindrical sections, the slope plate may be secured to the tank shell in one piece without being separated into two separate portions. For example, if the slope plate did not extend into the center section C3, then the slope plate could be welded to sections C1 and C2 before section C3 was inserted.

Referring to FIG. 6, it is noted that the lateral edge 32 of slope plate 24 forms an angle A of around 55 with respect to the adjacent inner surface of tank shell 18. Thus, a weld 33 may be made in the space formed between lateral edge 32 and inner surface of tank shell 18 which generally provides a continuation of the upper surface of slope plate 24. It will be apparent from FIGS. 3-6 that weld joint 33 is under compressive stress caused by the weight of insert 24 and the weight of the lading.

As shown specifically in FIGS. 8-10, a heating coil may be provided in void volume 34 to aid in the unloading of ladings. It is desirable to heat some ladings before unloading particularly those ladings having a high viscosity such as tar or molasses, and the most critical area for heating is the bottom ofthe tank. Steam may be inserted within inlet 52 to coil section 54. An outlet 56 is provided for an adjacent coil section 57 connected to section 54 by cross section 58. In this manner, a very effective heating arrangement is provided for the bottom of tank 18.

What is claimed is:

1. In a railway tank car having a horizontally disposed cylindrical tank shell with end heads and bottom discharge means on the tank shell generally centrally of the length of the tank shell; the improvement comprising, an elongate slope plate extending from each end head toward the bottom discharge means and secured to the inner surface of the tank shell along the bottom of the cylindrical tank shell, each slope plate inclined downwardly and tapering in width from the associated end head toward the center of the car, each of said slope plates being arcuate in transverse cross section and having an outwardly bowed convex upper surface to form a relatively narrow flow channel along each side of the slope plate thereby effectively draining the tank car of practically all liquid lading.

2. In a railway tank car as set forth in claim 1 wherein the entire space below each slope plate is filled with heat insulating material which provides support for the slope plates.

3. In a railway tank car as set forth in claim 2 wherein each insulating material under each slope plate is a cellular structure resilient enough to continue to fill the space between the slope sheet and the bottom of the tank when the tank undergoes a deformation.

4. In a railway tank car as set forth in claim 2 including heating conduits located in the spaces below the slope plates.

5. In a railway tank car as set forth in claim 4 wherein each slope plate forms a top wall of one of said heating conduits.

6. In a railway tank car having a horizontally disposed cylindrical tank shell with end heads and bottom discharge means on the tank shell generally centrally of the length of the tank shell; the improvement comprising, an elongate slope plate extending from each end head toward the bottom discharge means and secured to the inner surface of the tank shell along the bottom of the cylindrical tank shell, each slope plate tapering in width and inclined downwardly at a constant rate from the associated end head toward the center of the car, each of said slope plates being struck from a radius identical to the radius of the cylindrical tank shell and having an outwardly bowed convex upper surface to form a relatively narrow flow channel along each side of each slope plate, and weld material between the lateral edges of said slope plates and the inner surface of the tank shell to secure the slope plates to the tank shell and forming generally a continuation of the upper surface of the slope plates.

7. In a railway tank car having a horizontally disposed cylindrical tank shell with end heads and bottom discharge means on the tank shell generally centrally of tant radius and having an outwardly bowed convex upper surface to form a relatively narrow flow channel along each side of the slope plate, each of said plates forming with the subjacent tank shella cavity, and heating conduits located in the cavity below the slope plates. 

1. In a railway tank car having a horizontally disposed cylindrical tank shell with end heads and bottom discharge means on the tank shell generally centrally of the length of the tank shell; the improvement comprising, an elongate slope plate extending from each end head toward the bottom discharge means and secured to the inner surface of the tank shell along the bottom of the cylindrical tank shell, each slope plate inclined downwardly and tapering in width from the associated end head toward the center of the car, each of said slope plates being arcuate in transverse cross section and having an outwardly bowed convex upper surface to form a relatively narrow flow channel along each side of the slope plate thereby effectively draining the tank car of practically all liquid lading.
 2. In a railway tank car as set forth in claim 1 wherein the entire space below each slope plate is filled with heat insulating material which provides support for the slope plates.
 3. In a railway tank car as set forth in claim 2 wherein each insulating material under each slope plate is a cellular structure resilient enough to continue to fill the space between the slope sheet and the bottom of the tank when the tank undergoes a deformation.
 4. In a railway tank car as set forth in claim 2 including heating conduits located in the spaces below the slope plates.
 5. In a railway tank car as set forth in claim 4 wherein each slope plate forms a top wall of one of said heating conduits.
 6. In a railway tank car having a horizontally disposed cylindrical tank shell with end heads and bottom discharge means on the tank shell generally centrally of the length of the tank shell; the improvement comprising, an elongate slope plate extending from each end head toward the bottom discharge means and secured to the inner surface of the tank shell along the bottom of the cylindrical tank shell, each slope plate tapering in width and inclined downwardly at a constant rate from the associated end head toward the center of the car, each of said slope plates being struck from a radius identical to the radius of the cylindrical tank shell and having an outwardly bowed convex upper surface to form a relatively narrow flow channel along each side of each slope plate, and weld material between the lateral edges of said slope plates and the inner surface of the tank shell to secure the slope plates to the tank shell and forming generally a continuation of the upper surface of the slope plates.
 7. In a railway tank car having a horizontally disposed cylindrical tank shell with end heads and bottom discharge means on the tank shell generally centrally of the length of the tank shell; the improvement comprising, an elongate slope plate extending from each end head toward the bottom discharge means and secured to the inner surface of the tank shell along the bottom of the cylindrical tank shell, each slope plate tapering in width and inclined downwardly at a constant rate from the associated end head toward the center of the car, each of said slope plates being struck from a constant radius and having an outwardly bowed convex upper surface to form a relatively narrow flow channel along each side of the slope plate, each of said plates forming with the subjacent tank shell a cavity, and heating conduits located in the cavity below the slope plates. 